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<a class="jxr_linenumber" name="1" href="#1">1</a>   <em class="jxr_comment">/*</em>
<a class="jxr_linenumber" name="2" href="#2">2</a>   <em class="jxr_comment"> *  Licensed to the Apache Software Foundation (ASF) under one</em>
<a class="jxr_linenumber" name="3" href="#3">3</a>   <em class="jxr_comment"> *  or more contributor license agreements.  See the NOTICE file</em>
<a class="jxr_linenumber" name="4" href="#4">4</a>   <em class="jxr_comment"> *  distributed with this work for additional information</em>
<a class="jxr_linenumber" name="5" href="#5">5</a>   <em class="jxr_comment"> *  regarding copyright ownership.  The ASF licenses this file</em>
<a class="jxr_linenumber" name="6" href="#6">6</a>   <em class="jxr_comment"> *  to you under the Apache License, Version 2.0 (the</em>
<a class="jxr_linenumber" name="7" href="#7">7</a>   <em class="jxr_comment"> *  "License"); you may not use this file except in compliance</em>
<a class="jxr_linenumber" name="8" href="#8">8</a>   <em class="jxr_comment"> *  with the License.  You may obtain a copy of the License at</em>
<a class="jxr_linenumber" name="9" href="#9">9</a>   <em class="jxr_comment"> *</em>
<a class="jxr_linenumber" name="10" href="#10">10</a>  <em class="jxr_comment"> *    <a href="http://www.apache.org/licenses/LICENSE-2.0" target="alexandria_uri">http://www.apache.org/licenses/LICENSE-2.0</a></em>
<a class="jxr_linenumber" name="11" href="#11">11</a>  <em class="jxr_comment"> *</em>
<a class="jxr_linenumber" name="12" href="#12">12</a>  <em class="jxr_comment"> *  Unless required by applicable law or agreed to in writing,</em>
<a class="jxr_linenumber" name="13" href="#13">13</a>  <em class="jxr_comment"> *  software distributed under the License is distributed on an</em>
<a class="jxr_linenumber" name="14" href="#14">14</a>  <em class="jxr_comment"> *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY</em>
<a class="jxr_linenumber" name="15" href="#15">15</a>  <em class="jxr_comment"> *  KIND, either express or implied.  See the License for the</em>
<a class="jxr_linenumber" name="16" href="#16">16</a>  <em class="jxr_comment"> *  specific language governing permissions and limitations</em>
<a class="jxr_linenumber" name="17" href="#17">17</a>  <em class="jxr_comment"> *  under the License.</em>
<a class="jxr_linenumber" name="18" href="#18">18</a>  <em class="jxr_comment"> *</em>
<a class="jxr_linenumber" name="19" href="#19">19</a>  <em class="jxr_comment"> */</em>
<a class="jxr_linenumber" name="20" href="#20">20</a>  <strong class="jxr_keyword">package</strong> org.apache.directory.mavibot.btree;
<a class="jxr_linenumber" name="21" href="#21">21</a>  
<a class="jxr_linenumber" name="22" href="#22">22</a>  
<a class="jxr_linenumber" name="23" href="#23">23</a>  <strong class="jxr_keyword">import</strong> java.io.Closeable;
<a class="jxr_linenumber" name="24" href="#24">24</a>  <strong class="jxr_keyword">import</strong> java.io.EOFException;
<a class="jxr_linenumber" name="25" href="#25">25</a>  <strong class="jxr_keyword">import</strong> java.io.File;
<a class="jxr_linenumber" name="26" href="#26">26</a>  <strong class="jxr_keyword">import</strong> java.io.FileOutputStream;
<a class="jxr_linenumber" name="27" href="#27">27</a>  <strong class="jxr_keyword">import</strong> java.io.IOException;
<a class="jxr_linenumber" name="28" href="#28">28</a>  <strong class="jxr_keyword">import</strong> java.io.RandomAccessFile;
<a class="jxr_linenumber" name="29" href="#29">29</a>  <strong class="jxr_keyword">import</strong> java.nio.ByteBuffer;
<a class="jxr_linenumber" name="30" href="#30">30</a>  <strong class="jxr_keyword">import</strong> java.nio.channels.FileChannel;
<a class="jxr_linenumber" name="31" href="#31">31</a>  <strong class="jxr_keyword">import</strong> java.util.concurrent.ConcurrentLinkedQueue;
<a class="jxr_linenumber" name="32" href="#32">32</a>  <strong class="jxr_keyword">import</strong> java.util.concurrent.locks.ReentrantLock;
<a class="jxr_linenumber" name="33" href="#33">33</a>  
<a class="jxr_linenumber" name="34" href="#34">34</a>  <strong class="jxr_keyword">import</strong> org.apache.directory.mavibot.btree.exception.InitializationException;
<a class="jxr_linenumber" name="35" href="#35">35</a>  <strong class="jxr_keyword">import</strong> org.apache.directory.mavibot.btree.exception.KeyNotFoundException;
<a class="jxr_linenumber" name="36" href="#36">36</a>  <strong class="jxr_keyword">import</strong> org.apache.directory.mavibot.btree.exception.MissingSerializerException;
<a class="jxr_linenumber" name="37" href="#37">37</a>  <strong class="jxr_keyword">import</strong> org.apache.directory.mavibot.btree.serializer.BufferHandler;
<a class="jxr_linenumber" name="38" href="#38">38</a>  <strong class="jxr_keyword">import</strong> org.apache.directory.mavibot.btree.serializer.LongSerializer;
<a class="jxr_linenumber" name="39" href="#39">39</a>  <strong class="jxr_keyword">import</strong> org.slf4j.Logger;
<a class="jxr_linenumber" name="40" href="#40">40</a>  <strong class="jxr_keyword">import</strong> org.slf4j.LoggerFactory;
<a class="jxr_linenumber" name="41" href="#41">41</a>  
<a class="jxr_linenumber" name="42" href="#42">42</a>  
<a class="jxr_linenumber" name="43" href="#43">43</a>  <em class="jxr_javadoccomment">/**</em>
<a class="jxr_linenumber" name="44" href="#44">44</a>  <em class="jxr_javadoccomment"> * The B+Tree MVCC data structure.</em>
<a class="jxr_linenumber" name="45" href="#45">45</a>  <em class="jxr_javadoccomment"> *</em>
<a class="jxr_linenumber" name="46" href="#46">46</a>  <em class="jxr_javadoccomment"> * @param &lt;K&gt; The type for the keys</em>
<a class="jxr_linenumber" name="47" href="#47">47</a>  <em class="jxr_javadoccomment"> * @param &lt;V&gt; The type for the stored values</em>
<a class="jxr_linenumber" name="48" href="#48">48</a>  <em class="jxr_javadoccomment"> *</em>
<a class="jxr_linenumber" name="49" href="#49">49</a>  <em class="jxr_javadoccomment"> * @author &lt;a href="<a href="mailto:dev@directory.apache.org" target="alexandria_uri">mailto:dev@directory.apache.org</a>"&gt;Apache Directory Project&lt;/a&gt;</em>
<a class="jxr_linenumber" name="50" href="#50">50</a>  <em class="jxr_javadoccomment"> */</em>
<a class="jxr_linenumber" name="51" href="#51">51</a>  <em class="jxr_comment">/*<em class="jxr_comment"> No qualifier */</em><strong class="jxr_keyword">class</strong> InMemoryBTree&lt;K, V&gt; <strong class="jxr_keyword">extends</strong> AbstractBTree&lt;K, V&gt; <strong class="jxr_keyword">implements</strong> Closeable</em>
<a class="jxr_linenumber" name="52" href="#52">52</a>  {
<a class="jxr_linenumber" name="53" href="#53">53</a>      <em class="jxr_javadoccomment">/**</em><em class="jxr_javadoccomment"> The LoggerFactory used by this class */</em>
<a class="jxr_linenumber" name="54" href="#54">54</a>      <strong class="jxr_keyword">protected</strong> <strong class="jxr_keyword">static</strong> <strong class="jxr_keyword">final</strong> Logger LOG = LoggerFactory.getLogger( InMemoryBTree.<strong class="jxr_keyword">class</strong> );
<a class="jxr_linenumber" name="55" href="#55">55</a>  
<a class="jxr_linenumber" name="56" href="#56">56</a>      <em class="jxr_javadoccomment">/**</em><em class="jxr_javadoccomment"> The default journal name */</em>
<a class="jxr_linenumber" name="57" href="#57">57</a>      <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">static</strong> <strong class="jxr_keyword">final</strong> String DEFAULT_JOURNAL = <span class="jxr_string">"mavibot.log"</span>;
<a class="jxr_linenumber" name="58" href="#58">58</a>  
<a class="jxr_linenumber" name="59" href="#59">59</a>      <em class="jxr_javadoccomment">/**</em><em class="jxr_javadoccomment"> The default data file suffix */</em>
<a class="jxr_linenumber" name="60" href="#60">60</a>      <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">static</strong> <strong class="jxr_keyword">final</strong> String DATA_SUFFIX = <span class="jxr_string">".db"</span>;
<a class="jxr_linenumber" name="61" href="#61">61</a>  
<a class="jxr_linenumber" name="62" href="#62">62</a>      <em class="jxr_javadoccomment">/**</em><em class="jxr_javadoccomment"> The default journal file suffix */</em>
<a class="jxr_linenumber" name="63" href="#63">63</a>      <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">static</strong> <strong class="jxr_keyword">final</strong> String JOURNAL_SUFFIX = <span class="jxr_string">".log"</span>;
<a class="jxr_linenumber" name="64" href="#64">64</a>  
<a class="jxr_linenumber" name="65" href="#65">65</a>      <em class="jxr_javadoccomment">/**</em><em class="jxr_javadoccomment"> The type to use to create the keys */</em>
<a class="jxr_linenumber" name="66" href="#66">66</a>      <em class="jxr_javadoccomment">/**</em><em class="jxr_javadoccomment"> The associated file. If null, this is an in-memory btree  */</em>
<a class="jxr_linenumber" name="67" href="#67">67</a>      <strong class="jxr_keyword">private</strong> File file;
<a class="jxr_linenumber" name="68" href="#68">68</a>  
<a class="jxr_linenumber" name="69" href="#69">69</a>      <em class="jxr_javadoccomment">/**</em><em class="jxr_javadoccomment"> A flag used to tell the <a href="../../../../../org/apache/directory/mavibot/btree/BTree.html">BTree</a> that the journal is activated */</em>
<a class="jxr_linenumber" name="70" href="#70">70</a>      <strong class="jxr_keyword">private</strong> <strong class="jxr_keyword">boolean</strong> withJournal;
<a class="jxr_linenumber" name="71" href="#71">71</a>  
<a class="jxr_linenumber" name="72" href="#72">72</a>      <em class="jxr_javadoccomment">/**</em><em class="jxr_javadoccomment"> The associated journal. If null, this is an in-memory btree  */</em>
<a class="jxr_linenumber" name="73" href="#73">73</a>      <strong class="jxr_keyword">private</strong> File journal;
<a class="jxr_linenumber" name="74" href="#74">74</a>  
<a class="jxr_linenumber" name="75" href="#75">75</a>      <strong class="jxr_keyword">private</strong> File envDir;
<a class="jxr_linenumber" name="76" href="#76">76</a>  
<a class="jxr_linenumber" name="77" href="#77">77</a>      <strong class="jxr_keyword">private</strong> FileChannel journalChannel = <strong class="jxr_keyword">null</strong>;
<a class="jxr_linenumber" name="78" href="#78">78</a>  
<a class="jxr_linenumber" name="79" href="#79">79</a>  
<a class="jxr_linenumber" name="80" href="#80">80</a>      <em class="jxr_javadoccomment">/**</em>
<a class="jxr_linenumber" name="81" href="#81">81</a>  <em class="jxr_javadoccomment">     * Creates a new BTree, with no initialization.</em>
<a class="jxr_linenumber" name="82" href="#82">82</a>  <em class="jxr_javadoccomment">     */</em>
<a class="jxr_linenumber" name="83" href="#83">83</a>      <em class="jxr_comment">/*<em class="jxr_comment"> no qualifier */</em><a href="../../../../../org/apache/directory/mavibot/btree/InMemoryBTree.html">InMemoryBTree</a>()</em>
<a class="jxr_linenumber" name="84" href="#84">84</a>      {
<a class="jxr_linenumber" name="85" href="#85">85</a>          <strong class="jxr_keyword">super</strong>();
<a class="jxr_linenumber" name="86" href="#86">86</a>          btreeHeader = <strong class="jxr_keyword">new</strong> <a href="../../../../../org/apache/directory/mavibot/btree/BTreeHeader.html">BTreeHeader</a>();
<a class="jxr_linenumber" name="87" href="#87">87</a>          setType( BTreeTypeEnum.IN_MEMORY );
<a class="jxr_linenumber" name="88" href="#88">88</a>      }
<a class="jxr_linenumber" name="89" href="#89">89</a>  
<a class="jxr_linenumber" name="90" href="#90">90</a>  
<a class="jxr_linenumber" name="91" href="#91">91</a>      <em class="jxr_javadoccomment">/**</em>
<a class="jxr_linenumber" name="92" href="#92">92</a>  <em class="jxr_javadoccomment">     * Creates a new in-memory BTree using the BTreeConfiguration to initialize the</em>
<a class="jxr_linenumber" name="93" href="#93">93</a>  <em class="jxr_javadoccomment">     * BTree</em>
<a class="jxr_linenumber" name="94" href="#94">94</a>  <em class="jxr_javadoccomment">     *</em>
<a class="jxr_linenumber" name="95" href="#95">95</a>  <em class="jxr_javadoccomment">     * @param configuration The configuration to use</em>
<a class="jxr_linenumber" name="96" href="#96">96</a>  <em class="jxr_javadoccomment">     */</em>
<a class="jxr_linenumber" name="97" href="#97">97</a>      <em class="jxr_comment">/*<em class="jxr_comment"> no qualifier */</em><a href="../../../../../org/apache/directory/mavibot/btree/InMemoryBTree.html">InMemoryBTree</a>( InMemoryBTreeConfiguration&lt;K, V&gt; configuration )</em>
<a class="jxr_linenumber" name="98" href="#98">98</a>      {
<a class="jxr_linenumber" name="99" href="#99">99</a>          <strong class="jxr_keyword">super</strong>();
<a class="jxr_linenumber" name="100" href="#100">100</a>         String name = configuration.getName();
<a class="jxr_linenumber" name="101" href="#101">101</a> 
<a class="jxr_linenumber" name="102" href="#102">102</a>         <strong class="jxr_keyword">if</strong> ( name == <strong class="jxr_keyword">null</strong> )
<a class="jxr_linenumber" name="103" href="#103">103</a>         {
<a class="jxr_linenumber" name="104" href="#104">104</a>             <strong class="jxr_keyword">throw</strong> <strong class="jxr_keyword">new</strong> IllegalArgumentException( <span class="jxr_string">"BTree name cannot be null"</span> );
<a class="jxr_linenumber" name="105" href="#105">105</a>         }
<a class="jxr_linenumber" name="106" href="#106">106</a> 
<a class="jxr_linenumber" name="107" href="#107">107</a>         String filePath = configuration.getFilePath();
<a class="jxr_linenumber" name="108" href="#108">108</a> 
<a class="jxr_linenumber" name="109" href="#109">109</a>         <strong class="jxr_keyword">if</strong> ( filePath != <strong class="jxr_keyword">null</strong> )
<a class="jxr_linenumber" name="110" href="#110">110</a>         {
<a class="jxr_linenumber" name="111" href="#111">111</a>             envDir = <strong class="jxr_keyword">new</strong> File( filePath );
<a class="jxr_linenumber" name="112" href="#112">112</a>         }
<a class="jxr_linenumber" name="113" href="#113">113</a> 
<a class="jxr_linenumber" name="114" href="#114">114</a>         btreeHeader = <strong class="jxr_keyword">new</strong> <a href="../../../../../org/apache/directory/mavibot/btree/BTreeHeader.html">BTreeHeader</a>();
<a class="jxr_linenumber" name="115" href="#115">115</a>         btreeHeader.setName( name );
<a class="jxr_linenumber" name="116" href="#116">116</a>         btreeHeader.setPageSize( configuration.getPageSize() );
<a class="jxr_linenumber" name="117" href="#117">117</a> 
<a class="jxr_linenumber" name="118" href="#118">118</a>         keySerializer = configuration.getKeySerializer();
<a class="jxr_linenumber" name="119" href="#119">119</a>         btreeHeader.setKeySerializerFQCN( keySerializer.getClass().getName() );
<a class="jxr_linenumber" name="120" href="#120">120</a> 
<a class="jxr_linenumber" name="121" href="#121">121</a>         valueSerializer = configuration.getValueSerializer();
<a class="jxr_linenumber" name="122" href="#122">122</a>         btreeHeader.setValueSerializerFQCN( valueSerializer.getClass().getName() );
<a class="jxr_linenumber" name="123" href="#123">123</a> 
<a class="jxr_linenumber" name="124" href="#124">124</a>         readTimeOut = configuration.getReadTimeOut();
<a class="jxr_linenumber" name="125" href="#125">125</a>         writeBufferSize = configuration.getWriteBufferSize();
<a class="jxr_linenumber" name="126" href="#126">126</a>         btreeHeader.setAllowDuplicates( configuration.isAllowDuplicates() );
<a class="jxr_linenumber" name="127" href="#127">127</a>         setType( configuration.getType() );
<a class="jxr_linenumber" name="128" href="#128">128</a> 
<a class="jxr_linenumber" name="129" href="#129">129</a>         <strong class="jxr_keyword">if</strong> ( keySerializer.getComparator() == <strong class="jxr_keyword">null</strong> )
<a class="jxr_linenumber" name="130" href="#130">130</a>         {
<a class="jxr_linenumber" name="131" href="#131">131</a>             <strong class="jxr_keyword">throw</strong> <strong class="jxr_keyword">new</strong> IllegalArgumentException( <span class="jxr_string">"Comparator should not be null"</span> );
<a class="jxr_linenumber" name="132" href="#132">132</a>         }
<a class="jxr_linenumber" name="133" href="#133">133</a> 
<a class="jxr_linenumber" name="134" href="#134">134</a>         <em class="jxr_comment">// Create the first root page, with revision 0L. It will be empty</em>
<a class="jxr_linenumber" name="135" href="#135">135</a>         <em class="jxr_comment">// and increment the revision at the same time</em>
<a class="jxr_linenumber" name="136" href="#136">136</a>         rootPage = <strong class="jxr_keyword">new</strong> InMemoryLeaf&lt;K, V&gt;( <strong class="jxr_keyword">this</strong> );
<a class="jxr_linenumber" name="137" href="#137">137</a> 
<a class="jxr_linenumber" name="138" href="#138">138</a>         <em class="jxr_comment">// Now, initialize the BTree</em>
<a class="jxr_linenumber" name="139" href="#139">139</a>         <strong class="jxr_keyword">try</strong>
<a class="jxr_linenumber" name="140" href="#140">140</a>         {
<a class="jxr_linenumber" name="141" href="#141">141</a>             init();
<a class="jxr_linenumber" name="142" href="#142">142</a>         }
<a class="jxr_linenumber" name="143" href="#143">143</a>         <strong class="jxr_keyword">catch</strong> ( IOException ioe )
<a class="jxr_linenumber" name="144" href="#144">144</a>         {
<a class="jxr_linenumber" name="145" href="#145">145</a>             <strong class="jxr_keyword">throw</strong> <strong class="jxr_keyword">new</strong> <a href="../../../../../org/apache/directory/mavibot/btree/exception/InitializationException.html">InitializationException</a>( ioe.getMessage() );
<a class="jxr_linenumber" name="146" href="#146">146</a>         }
<a class="jxr_linenumber" name="147" href="#147">147</a>     }
<a class="jxr_linenumber" name="148" href="#148">148</a> 
<a class="jxr_linenumber" name="149" href="#149">149</a> 
<a class="jxr_linenumber" name="150" href="#150">150</a>     <em class="jxr_javadoccomment">/**</em>
<a class="jxr_linenumber" name="151" href="#151">151</a> <em class="jxr_javadoccomment">     * Initialize the BTree.</em>
<a class="jxr_linenumber" name="152" href="#152">152</a> <em class="jxr_javadoccomment">     *</em>
<a class="jxr_linenumber" name="153" href="#153">153</a> <em class="jxr_javadoccomment">     * @throws IOException If we get some exception while initializing the BTree</em>
<a class="jxr_linenumber" name="154" href="#154">154</a> <em class="jxr_javadoccomment">     */</em>
<a class="jxr_linenumber" name="155" href="#155">155</a>     <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">void</strong> init() <strong class="jxr_keyword">throws</strong> IOException
<a class="jxr_linenumber" name="156" href="#156">156</a>     {
<a class="jxr_linenumber" name="157" href="#157">157</a>         <em class="jxr_comment">// if not in-memory then default to persist mode instead of managed</em>
<a class="jxr_linenumber" name="158" href="#158">158</a>         <strong class="jxr_keyword">if</strong> ( envDir != <strong class="jxr_keyword">null</strong> )
<a class="jxr_linenumber" name="159" href="#159">159</a>         {
<a class="jxr_linenumber" name="160" href="#160">160</a>             <strong class="jxr_keyword">if</strong> ( !envDir.exists() )
<a class="jxr_linenumber" name="161" href="#161">161</a>             {
<a class="jxr_linenumber" name="162" href="#162">162</a>                 <strong class="jxr_keyword">boolean</strong> created = envDir.mkdirs();
<a class="jxr_linenumber" name="163" href="#163">163</a>                 <strong class="jxr_keyword">if</strong> ( !created )
<a class="jxr_linenumber" name="164" href="#164">164</a>                 {
<a class="jxr_linenumber" name="165" href="#165">165</a>                     <strong class="jxr_keyword">throw</strong> <strong class="jxr_keyword">new</strong> IllegalStateException( <span class="jxr_string">"Could not create the directory "</span> + envDir + <span class="jxr_string">" for storing data"</span> );
<a class="jxr_linenumber" name="166" href="#166">166</a>                 }
<a class="jxr_linenumber" name="167" href="#167">167</a>             }
<a class="jxr_linenumber" name="168" href="#168">168</a> 
<a class="jxr_linenumber" name="169" href="#169">169</a>             <strong class="jxr_keyword">this</strong>.file = <strong class="jxr_keyword">new</strong> File( envDir, btreeHeader.getName() + DATA_SUFFIX );
<a class="jxr_linenumber" name="170" href="#170">170</a> 
<a class="jxr_linenumber" name="171" href="#171">171</a>             <strong class="jxr_keyword">this</strong>.journal = <strong class="jxr_keyword">new</strong> File( envDir, file.getName() + JOURNAL_SUFFIX );
<a class="jxr_linenumber" name="172" href="#172">172</a>             setType( BTreeTypeEnum.BACKED_ON_DISK );
<a class="jxr_linenumber" name="173" href="#173">173</a>         }
<a class="jxr_linenumber" name="174" href="#174">174</a> 
<a class="jxr_linenumber" name="175" href="#175">175</a>         <em class="jxr_comment">// Create the queue containing the pending read transactions</em>
<a class="jxr_linenumber" name="176" href="#176">176</a>         readTransactions = <strong class="jxr_keyword">new</strong> ConcurrentLinkedQueue&lt;ReadTransaction&lt;K, V&gt;&gt;();
<a class="jxr_linenumber" name="177" href="#177">177</a> 
<a class="jxr_linenumber" name="178" href="#178">178</a>         writeLock = <strong class="jxr_keyword">new</strong> ReentrantLock();
<a class="jxr_linenumber" name="179" href="#179">179</a> 
<a class="jxr_linenumber" name="180" href="#180">180</a>         <em class="jxr_comment">// Check the files and create them if missing</em>
<a class="jxr_linenumber" name="181" href="#181">181</a>         <em class="jxr_comment">// Create the queue containing the modifications, if it's not a in-memory btree</em>
<a class="jxr_linenumber" name="182" href="#182">182</a>         <strong class="jxr_keyword">if</strong> ( getType() == BTreeTypeEnum.BACKED_ON_DISK )
<a class="jxr_linenumber" name="183" href="#183">183</a>         {
<a class="jxr_linenumber" name="184" href="#184">184</a>             <strong class="jxr_keyword">if</strong> ( file.length() &gt; 0 )
<a class="jxr_linenumber" name="185" href="#185">185</a>             {
<a class="jxr_linenumber" name="186" href="#186">186</a>                 <em class="jxr_comment">// We have some existing file, load it</em>
<a class="jxr_linenumber" name="187" href="#187">187</a>                 load( file );
<a class="jxr_linenumber" name="188" href="#188">188</a>             }
<a class="jxr_linenumber" name="189" href="#189">189</a> 
<a class="jxr_linenumber" name="190" href="#190">190</a>             withJournal = <strong class="jxr_keyword">true</strong>;
<a class="jxr_linenumber" name="191" href="#191">191</a> 
<a class="jxr_linenumber" name="192" href="#192">192</a>             FileOutputStream stream = <strong class="jxr_keyword">new</strong> FileOutputStream( journal );
<a class="jxr_linenumber" name="193" href="#193">193</a>             journalChannel = stream.getChannel();
<a class="jxr_linenumber" name="194" href="#194">194</a> 
<a class="jxr_linenumber" name="195" href="#195">195</a>             <em class="jxr_comment">// If the journal is not empty, we have to read it</em>
<a class="jxr_linenumber" name="196" href="#196">196</a>             <em class="jxr_comment">// and to apply all the modifications to the current file</em>
<a class="jxr_linenumber" name="197" href="#197">197</a>             <strong class="jxr_keyword">if</strong> ( journal.length() &gt; 0 )
<a class="jxr_linenumber" name="198" href="#198">198</a>             {
<a class="jxr_linenumber" name="199" href="#199">199</a>                 applyJournal();
<a class="jxr_linenumber" name="200" href="#200">200</a>             }
<a class="jxr_linenumber" name="201" href="#201">201</a>         }
<a class="jxr_linenumber" name="202" href="#202">202</a>         <strong class="jxr_keyword">else</strong>
<a class="jxr_linenumber" name="203" href="#203">203</a>         {
<a class="jxr_linenumber" name="204" href="#204">204</a>             setType( BTreeTypeEnum.IN_MEMORY );
<a class="jxr_linenumber" name="205" href="#205">205</a>         }
<a class="jxr_linenumber" name="206" href="#206">206</a> 
<a class="jxr_linenumber" name="207" href="#207">207</a>         <em class="jxr_comment">// Initialize the txnManager thread</em>
<a class="jxr_linenumber" name="208" href="#208">208</a>         <em class="jxr_comment">//FIXME we should NOT create a new transaction manager thread for each BTree</em>
<a class="jxr_linenumber" name="209" href="#209">209</a>         <em class="jxr_comment">//createTransactionManager();</em>
<a class="jxr_linenumber" name="210" href="#210">210</a>     }
<a class="jxr_linenumber" name="211" href="#211">211</a> 
<a class="jxr_linenumber" name="212" href="#212">212</a> 
<a class="jxr_linenumber" name="213" href="#213">213</a>     <em class="jxr_javadoccomment">/**</em>
<a class="jxr_linenumber" name="214" href="#214">214</a> <em class="jxr_javadoccomment">     * Close the BTree, cleaning up all the data structure</em>
<a class="jxr_linenumber" name="215" href="#215">215</a> <em class="jxr_javadoccomment">     */</em>
<a class="jxr_linenumber" name="216" href="#216">216</a>     <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">void</strong> close() <strong class="jxr_keyword">throws</strong> IOException
<a class="jxr_linenumber" name="217" href="#217">217</a>     {
<a class="jxr_linenumber" name="218" href="#218">218</a>         <em class="jxr_comment">// Stop the readTransaction thread</em>
<a class="jxr_linenumber" name="219" href="#219">219</a>         <em class="jxr_comment">// readTransactionsThread.interrupt();</em>
<a class="jxr_linenumber" name="220" href="#220">220</a>         <em class="jxr_comment">// readTransactions.clear();</em>
<a class="jxr_linenumber" name="221" href="#221">221</a> 
<a class="jxr_linenumber" name="222" href="#222">222</a>         <strong class="jxr_keyword">if</strong> ( getType() == BTreeTypeEnum.BACKED_ON_DISK )
<a class="jxr_linenumber" name="223" href="#223">223</a>         {
<a class="jxr_linenumber" name="224" href="#224">224</a>             <em class="jxr_comment">// Flush the data</em>
<a class="jxr_linenumber" name="225" href="#225">225</a>             flush();
<a class="jxr_linenumber" name="226" href="#226">226</a>             journalChannel.close();
<a class="jxr_linenumber" name="227" href="#227">227</a>         }
<a class="jxr_linenumber" name="228" href="#228">228</a> 
<a class="jxr_linenumber" name="229" href="#229">229</a>         rootPage = <strong class="jxr_keyword">null</strong>;
<a class="jxr_linenumber" name="230" href="#230">230</a>     }
<a class="jxr_linenumber" name="231" href="#231">231</a> 
<a class="jxr_linenumber" name="232" href="#232">232</a> 
<a class="jxr_linenumber" name="233" href="#233">233</a>     <em class="jxr_javadoccomment">/**</em>
<a class="jxr_linenumber" name="234" href="#234">234</a> <em class="jxr_javadoccomment">     *</em>
<a class="jxr_linenumber" name="235" href="#235">235</a> <em class="jxr_javadoccomment">     * Deletes the given &lt;key,value&gt; pair if both key and value match. If the given value is null</em>
<a class="jxr_linenumber" name="236" href="#236">236</a> <em class="jxr_javadoccomment">     * and there is no null value associated with the given key then the entry with the given key</em>
<a class="jxr_linenumber" name="237" href="#237">237</a> <em class="jxr_javadoccomment">     * will be removed.</em>
<a class="jxr_linenumber" name="238" href="#238">238</a> <em class="jxr_javadoccomment">     *</em>
<a class="jxr_linenumber" name="239" href="#239">239</a> <em class="jxr_javadoccomment">     * @param key The key to be removed</em>
<a class="jxr_linenumber" name="240" href="#240">240</a> <em class="jxr_javadoccomment">     * @param value The value to be removed (can be null, and when no null value exists the key will be removed irrespective of the value)</em>
<a class="jxr_linenumber" name="241" href="#241">241</a> <em class="jxr_javadoccomment">     * @param revision The revision to be associated with this operation</em>
<a class="jxr_linenumber" name="242" href="#242">242</a> <em class="jxr_javadoccomment">     * @return</em>
<a class="jxr_linenumber" name="243" href="#243">243</a> <em class="jxr_javadoccomment">     * @throws IOException</em>
<a class="jxr_linenumber" name="244" href="#244">244</a> <em class="jxr_javadoccomment">     */</em>
<a class="jxr_linenumber" name="245" href="#245">245</a>     <strong class="jxr_keyword">protected</strong> Tuple&lt;K, V&gt; delete( K key, V value, <strong class="jxr_keyword">long</strong> revision ) <strong class="jxr_keyword">throws</strong> IOException
<a class="jxr_linenumber" name="246" href="#246">246</a>     {
<a class="jxr_linenumber" name="247" href="#247">247</a>         writeLock.lock();
<a class="jxr_linenumber" name="248" href="#248">248</a> 
<a class="jxr_linenumber" name="249" href="#249">249</a>         <strong class="jxr_keyword">try</strong>
<a class="jxr_linenumber" name="250" href="#250">250</a>         {
<a class="jxr_linenumber" name="251" href="#251">251</a>             <em class="jxr_comment">// If the key exists, the existing value will be replaced. We store it</em>
<a class="jxr_linenumber" name="252" href="#252">252</a>             <em class="jxr_comment">// to return it to the caller.</em>
<a class="jxr_linenumber" name="253" href="#253">253</a>             Tuple&lt;K, V&gt; tuple = <strong class="jxr_keyword">null</strong>;
<a class="jxr_linenumber" name="254" href="#254">254</a> 
<a class="jxr_linenumber" name="255" href="#255">255</a>             <em class="jxr_comment">// Try to delete the entry starting from the root page. Here, the root</em>
<a class="jxr_linenumber" name="256" href="#256">256</a>             <em class="jxr_comment">// page may be either a Node or a Leaf</em>
<a class="jxr_linenumber" name="257" href="#257">257</a>             DeleteResult&lt;K, V&gt; result = rootPage.delete( revision, key, value, <strong class="jxr_keyword">null</strong>, -1 );
<a class="jxr_linenumber" name="258" href="#258">258</a> 
<a class="jxr_linenumber" name="259" href="#259">259</a>             <strong class="jxr_keyword">if</strong> ( result instanceof NotPresentResult )
<a class="jxr_linenumber" name="260" href="#260">260</a>             {
<a class="jxr_linenumber" name="261" href="#261">261</a>                 <em class="jxr_comment">// Key not found.</em>
<a class="jxr_linenumber" name="262" href="#262">262</a>                 <strong class="jxr_keyword">return</strong> <strong class="jxr_keyword">null</strong>;
<a class="jxr_linenumber" name="263" href="#263">263</a>             }
<a class="jxr_linenumber" name="264" href="#264">264</a> 
<a class="jxr_linenumber" name="265" href="#265">265</a>             <em class="jxr_comment">// Keep the oldRootPage so that we can later access it</em>
<a class="jxr_linenumber" name="266" href="#266">266</a>             Page&lt;K, V&gt; oldRootPage = rootPage;
<a class="jxr_linenumber" name="267" href="#267">267</a> 
<a class="jxr_linenumber" name="268" href="#268">268</a>             <strong class="jxr_keyword">if</strong> ( result instanceof RemoveResult )
<a class="jxr_linenumber" name="269" href="#269">269</a>             {
<a class="jxr_linenumber" name="270" href="#270">270</a>                 <em class="jxr_comment">// The element was found, and removed</em>
<a class="jxr_linenumber" name="271" href="#271">271</a>                 RemoveResult&lt;K, V&gt; removeResult = ( RemoveResult&lt;K, V&gt; ) result;
<a class="jxr_linenumber" name="272" href="#272">272</a> 
<a class="jxr_linenumber" name="273" href="#273">273</a>                 Page&lt;K, V&gt; modifiedPage = removeResult.getModifiedPage();
<a class="jxr_linenumber" name="274" href="#274">274</a> 
<a class="jxr_linenumber" name="275" href="#275">275</a>                 <em class="jxr_comment">// This is a new root</em>
<a class="jxr_linenumber" name="276" href="#276">276</a>                 rootPage = modifiedPage;
<a class="jxr_linenumber" name="277" href="#277">277</a>                 tuple = removeResult.getRemovedElement();
<a class="jxr_linenumber" name="278" href="#278">278</a>             }
<a class="jxr_linenumber" name="279" href="#279">279</a> 
<a class="jxr_linenumber" name="280" href="#280">280</a>             <strong class="jxr_keyword">if</strong> ( withJournal )
<a class="jxr_linenumber" name="281" href="#281">281</a>             {
<a class="jxr_linenumber" name="282" href="#282">282</a>                 <em class="jxr_comment">// Inject the modification into the modification queue</em>
<a class="jxr_linenumber" name="283" href="#283">283</a>                 writeToJournal( <strong class="jxr_keyword">new</strong> Deletion&lt;K, V&gt;( key ) );
<a class="jxr_linenumber" name="284" href="#284">284</a>             }
<a class="jxr_linenumber" name="285" href="#285">285</a> 
<a class="jxr_linenumber" name="286" href="#286">286</a>             <em class="jxr_comment">// Decrease the number of elements in the current tree if the deletion is successful</em>
<a class="jxr_linenumber" name="287" href="#287">287</a>             <strong class="jxr_keyword">if</strong> ( tuple != <strong class="jxr_keyword">null</strong> )
<a class="jxr_linenumber" name="288" href="#288">288</a>             {
<a class="jxr_linenumber" name="289" href="#289">289</a>                 btreeHeader.decrementNbElems();
<a class="jxr_linenumber" name="290" href="#290">290</a>             }
<a class="jxr_linenumber" name="291" href="#291">291</a> 
<a class="jxr_linenumber" name="292" href="#292">292</a>             <em class="jxr_comment">// Return the value we have found if it was modified</em>
<a class="jxr_linenumber" name="293" href="#293">293</a>             <strong class="jxr_keyword">return</strong> tuple;
<a class="jxr_linenumber" name="294" href="#294">294</a>         }
<a class="jxr_linenumber" name="295" href="#295">295</a>         <strong class="jxr_keyword">finally</strong>
<a class="jxr_linenumber" name="296" href="#296">296</a>         {
<a class="jxr_linenumber" name="297" href="#297">297</a>             <em class="jxr_comment">// See above</em>
<a class="jxr_linenumber" name="298" href="#298">298</a>             writeLock.unlock();
<a class="jxr_linenumber" name="299" href="#299">299</a>         }
<a class="jxr_linenumber" name="300" href="#300">300</a>     }
<a class="jxr_linenumber" name="301" href="#301">301</a> 
<a class="jxr_linenumber" name="302" href="#302">302</a> 
<a class="jxr_linenumber" name="303" href="#303">303</a>     <em class="jxr_javadoccomment">/**</em>
<a class="jxr_linenumber" name="304" href="#304">304</a> <em class="jxr_javadoccomment">     * Insert an entry in the BTree.</em>
<a class="jxr_linenumber" name="305" href="#305">305</a> <em class="jxr_javadoccomment">     * &lt;p&gt;</em>
<a class="jxr_linenumber" name="306" href="#306">306</a> <em class="jxr_javadoccomment">     * We will replace the value if the provided key already exists in the</em>
<a class="jxr_linenumber" name="307" href="#307">307</a> <em class="jxr_javadoccomment">     * btree.</em>
<a class="jxr_linenumber" name="308" href="#308">308</a> <em class="jxr_javadoccomment">     * &lt;p&gt;</em>
<a class="jxr_linenumber" name="309" href="#309">309</a> <em class="jxr_javadoccomment">     * The revision number is the revision to use to insert the data.</em>
<a class="jxr_linenumber" name="310" href="#310">310</a> <em class="jxr_javadoccomment">     *</em>
<a class="jxr_linenumber" name="311" href="#311">311</a> <em class="jxr_javadoccomment">     * @param key Inserted key</em>
<a class="jxr_linenumber" name="312" href="#312">312</a> <em class="jxr_javadoccomment">     * @param value Inserted value</em>
<a class="jxr_linenumber" name="313" href="#313">313</a> <em class="jxr_javadoccomment">     * @param revision The revision to use</em>
<a class="jxr_linenumber" name="314" href="#314">314</a> <em class="jxr_javadoccomment">     * @return an instance of the InsertResult.</em>
<a class="jxr_linenumber" name="315" href="#315">315</a> <em class="jxr_javadoccomment">     */</em>
<a class="jxr_linenumber" name="316" href="#316">316</a>     <em class="jxr_comment">/*<em class="jxr_comment"> no qualifier */</em>InsertResult&lt;K, V&gt; insert( K key, V value, <strong class="jxr_keyword">long</strong> revision ) <strong class="jxr_keyword">throws</strong> IOException</em>
<a class="jxr_linenumber" name="317" href="#317">317</a>     {
<a class="jxr_linenumber" name="318" href="#318">318</a>         <strong class="jxr_keyword">if</strong> ( key == <strong class="jxr_keyword">null</strong> )
<a class="jxr_linenumber" name="319" href="#319">319</a>         {
<a class="jxr_linenumber" name="320" href="#320">320</a>             <strong class="jxr_keyword">throw</strong> <strong class="jxr_keyword">new</strong> IllegalArgumentException( <span class="jxr_string">"Key must not be null"</span> );
<a class="jxr_linenumber" name="321" href="#321">321</a>         }
<a class="jxr_linenumber" name="322" href="#322">322</a> 
<a class="jxr_linenumber" name="323" href="#323">323</a>         <em class="jxr_comment">// If the key exists, the existing value will be replaced. We store it</em>
<a class="jxr_linenumber" name="324" href="#324">324</a>         <em class="jxr_comment">// to return it to the caller.</em>
<a class="jxr_linenumber" name="325" href="#325">325</a>         V modifiedValue = <strong class="jxr_keyword">null</strong>;
<a class="jxr_linenumber" name="326" href="#326">326</a> 
<a class="jxr_linenumber" name="327" href="#327">327</a>         <em class="jxr_comment">// Try to insert the new value in the tree at the right place,</em>
<a class="jxr_linenumber" name="328" href="#328">328</a>         <em class="jxr_comment">// starting from the root page. Here, the root page may be either</em>
<a class="jxr_linenumber" name="329" href="#329">329</a>         <em class="jxr_comment">// a Node or a Leaf</em>
<a class="jxr_linenumber" name="330" href="#330">330</a>         InsertResult&lt;K, V&gt; result = rootPage.insert( revision, key, value );
<a class="jxr_linenumber" name="331" href="#331">331</a> 
<a class="jxr_linenumber" name="332" href="#332">332</a>         <strong class="jxr_keyword">if</strong> ( result instanceof ModifyResult )
<a class="jxr_linenumber" name="333" href="#333">333</a>         {
<a class="jxr_linenumber" name="334" href="#334">334</a>             ModifyResult&lt;K, V&gt; modifyResult = ( ( ModifyResult&lt;K, V&gt; ) result );
<a class="jxr_linenumber" name="335" href="#335">335</a> 
<a class="jxr_linenumber" name="336" href="#336">336</a>             Page&lt;K, V&gt; modifiedPage = modifyResult.getModifiedPage();
<a class="jxr_linenumber" name="337" href="#337">337</a> 
<a class="jxr_linenumber" name="338" href="#338">338</a>             <em class="jxr_comment">// The root has just been modified, we haven't split it</em>
<a class="jxr_linenumber" name="339" href="#339">339</a>             <em class="jxr_comment">// Get it and make it the current root page</em>
<a class="jxr_linenumber" name="340" href="#340">340</a>             rootPage = modifiedPage;
<a class="jxr_linenumber" name="341" href="#341">341</a> 
<a class="jxr_linenumber" name="342" href="#342">342</a>             modifiedValue = modifyResult.getModifiedValue();
<a class="jxr_linenumber" name="343" href="#343">343</a>         }
<a class="jxr_linenumber" name="344" href="#344">344</a>         <strong class="jxr_keyword">else</strong>
<a class="jxr_linenumber" name="345" href="#345">345</a>         {
<a class="jxr_linenumber" name="346" href="#346">346</a>             <em class="jxr_comment">// We have split the old root, create a new one containing</em>
<a class="jxr_linenumber" name="347" href="#347">347</a>             <em class="jxr_comment">// only the pivotal we got back</em>
<a class="jxr_linenumber" name="348" href="#348">348</a>             SplitResult&lt;K, V&gt; splitResult = ( ( SplitResult&lt;K, V&gt; ) result );
<a class="jxr_linenumber" name="349" href="#349">349</a> 
<a class="jxr_linenumber" name="350" href="#350">350</a>             K pivot = splitResult.getPivot();
<a class="jxr_linenumber" name="351" href="#351">351</a>             Page&lt;K, V&gt; leftPage = splitResult.getLeftPage();
<a class="jxr_linenumber" name="352" href="#352">352</a>             Page&lt;K, V&gt; rightPage = splitResult.getRightPage();
<a class="jxr_linenumber" name="353" href="#353">353</a>             Page&lt;K, V&gt; newRootPage = <strong class="jxr_keyword">null</strong>;
<a class="jxr_linenumber" name="354" href="#354">354</a> 
<a class="jxr_linenumber" name="355" href="#355">355</a>             <em class="jxr_comment">// Create the new rootPage</em>
<a class="jxr_linenumber" name="356" href="#356">356</a>             newRootPage = <strong class="jxr_keyword">new</strong> InMemoryNode&lt;K, V&gt;( <strong class="jxr_keyword">this</strong>, revision, pivot, leftPage, rightPage );
<a class="jxr_linenumber" name="357" href="#357">357</a> 
<a class="jxr_linenumber" name="358" href="#358">358</a>             rootPage = newRootPage;
<a class="jxr_linenumber" name="359" href="#359">359</a>         }
<a class="jxr_linenumber" name="360" href="#360">360</a> 
<a class="jxr_linenumber" name="361" href="#361">361</a>         <em class="jxr_comment">// Inject the modification into the modification queue</em>
<a class="jxr_linenumber" name="362" href="#362">362</a>         <strong class="jxr_keyword">if</strong> ( withJournal )
<a class="jxr_linenumber" name="363" href="#363">363</a>         {
<a class="jxr_linenumber" name="364" href="#364">364</a>             writeToJournal( <strong class="jxr_keyword">new</strong> Addition&lt;K, V&gt;( key, value ) );
<a class="jxr_linenumber" name="365" href="#365">365</a>         }
<a class="jxr_linenumber" name="366" href="#366">366</a> 
<a class="jxr_linenumber" name="367" href="#367">367</a>         <em class="jxr_comment">// Increase the number of element in the current tree if the insertion is successful</em>
<a class="jxr_linenumber" name="368" href="#368">368</a>         <em class="jxr_comment">// and does not replace an element</em>
<a class="jxr_linenumber" name="369" href="#369">369</a>         <strong class="jxr_keyword">if</strong> ( modifiedValue == <strong class="jxr_keyword">null</strong> )
<a class="jxr_linenumber" name="370" href="#370">370</a>         {
<a class="jxr_linenumber" name="371" href="#371">371</a>             btreeHeader.incrementNbElems();
<a class="jxr_linenumber" name="372" href="#372">372</a>         }
<a class="jxr_linenumber" name="373" href="#373">373</a> 
<a class="jxr_linenumber" name="374" href="#374">374</a>         <em class="jxr_comment">// Return the value we have found if it was modified</em>
<a class="jxr_linenumber" name="375" href="#375">375</a>         <strong class="jxr_keyword">return</strong> result;
<a class="jxr_linenumber" name="376" href="#376">376</a>     }
<a class="jxr_linenumber" name="377" href="#377">377</a> 
<a class="jxr_linenumber" name="378" href="#378">378</a> 
<a class="jxr_linenumber" name="379" href="#379">379</a>     <em class="jxr_javadoccomment">/**</em>
<a class="jxr_linenumber" name="380" href="#380">380</a> <em class="jxr_javadoccomment">     * Write the data in the ByteBuffer, and eventually on disk if needed.</em>
<a class="jxr_linenumber" name="381" href="#381">381</a> <em class="jxr_javadoccomment">     *</em>
<a class="jxr_linenumber" name="382" href="#382">382</a> <em class="jxr_javadoccomment">     * @param channel The channel we want to write to</em>
<a class="jxr_linenumber" name="383" href="#383">383</a> <em class="jxr_javadoccomment">     * @param bb The ByteBuffer we want to feed</em>
<a class="jxr_linenumber" name="384" href="#384">384</a> <em class="jxr_javadoccomment">     * @param buffer The data to inject</em>
<a class="jxr_linenumber" name="385" href="#385">385</a> <em class="jxr_javadoccomment">     * @throws IOException If the write failed</em>
<a class="jxr_linenumber" name="386" href="#386">386</a> <em class="jxr_javadoccomment">     */</em>
<a class="jxr_linenumber" name="387" href="#387">387</a>     <strong class="jxr_keyword">private</strong> <strong class="jxr_keyword">void</strong> writeBuffer( FileChannel channel, ByteBuffer bb, byte[] buffer ) <strong class="jxr_keyword">throws</strong> IOException
<a class="jxr_linenumber" name="388" href="#388">388</a>     {
<a class="jxr_linenumber" name="389" href="#389">389</a>         <strong class="jxr_keyword">int</strong> size = buffer.length;
<a class="jxr_linenumber" name="390" href="#390">390</a>         <strong class="jxr_keyword">int</strong> pos = 0;
<a class="jxr_linenumber" name="391" href="#391">391</a> 
<a class="jxr_linenumber" name="392" href="#392">392</a>         <em class="jxr_comment">// Loop until we have written all the data</em>
<a class="jxr_linenumber" name="393" href="#393">393</a>         <strong class="jxr_keyword">do</strong>
<a class="jxr_linenumber" name="394" href="#394">394</a>         {
<a class="jxr_linenumber" name="395" href="#395">395</a>             <strong class="jxr_keyword">if</strong> ( bb.remaining() &gt;= size )
<a class="jxr_linenumber" name="396" href="#396">396</a>             {
<a class="jxr_linenumber" name="397" href="#397">397</a>                 <em class="jxr_comment">// No flush, as the ByteBuffer is big enough</em>
<a class="jxr_linenumber" name="398" href="#398">398</a>                 bb.put( buffer, pos, size );
<a class="jxr_linenumber" name="399" href="#399">399</a>                 size = 0;
<a class="jxr_linenumber" name="400" href="#400">400</a>             }
<a class="jxr_linenumber" name="401" href="#401">401</a>             <strong class="jxr_keyword">else</strong>
<a class="jxr_linenumber" name="402" href="#402">402</a>             {
<a class="jxr_linenumber" name="403" href="#403">403</a>                 <em class="jxr_comment">// Flush the data on disk, reinitialize the ByteBuffer</em>
<a class="jxr_linenumber" name="404" href="#404">404</a>                 <strong class="jxr_keyword">int</strong> len = bb.remaining();
<a class="jxr_linenumber" name="405" href="#405">405</a>                 size -= len;
<a class="jxr_linenumber" name="406" href="#406">406</a>                 bb.put( buffer, pos, len );
<a class="jxr_linenumber" name="407" href="#407">407</a>                 pos += len;
<a class="jxr_linenumber" name="408" href="#408">408</a> 
<a class="jxr_linenumber" name="409" href="#409">409</a>                 bb.flip();
<a class="jxr_linenumber" name="410" href="#410">410</a> 
<a class="jxr_linenumber" name="411" href="#411">411</a>                 channel.write( bb );
<a class="jxr_linenumber" name="412" href="#412">412</a> 
<a class="jxr_linenumber" name="413" href="#413">413</a>                 bb.clear();
<a class="jxr_linenumber" name="414" href="#414">414</a>             }
<a class="jxr_linenumber" name="415" href="#415">415</a>         }
<a class="jxr_linenumber" name="416" href="#416">416</a>         <strong class="jxr_keyword">while</strong> ( size &gt; 0 );
<a class="jxr_linenumber" name="417" href="#417">417</a>     }
<a class="jxr_linenumber" name="418" href="#418">418</a> 
<a class="jxr_linenumber" name="419" href="#419">419</a> 
<a class="jxr_linenumber" name="420" href="#420">420</a>     <em class="jxr_javadoccomment">/**</em>
<a class="jxr_linenumber" name="421" href="#421">421</a> <em class="jxr_javadoccomment">     * Flush the latest revision to disk</em>
<a class="jxr_linenumber" name="422" href="#422">422</a> <em class="jxr_javadoccomment">     * @param file The file into which the data will be written</em>
<a class="jxr_linenumber" name="423" href="#423">423</a> <em class="jxr_javadoccomment">     */</em>
<a class="jxr_linenumber" name="424" href="#424">424</a>     <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">void</strong> flush( File file ) <strong class="jxr_keyword">throws</strong> IOException
<a class="jxr_linenumber" name="425" href="#425">425</a>     {
<a class="jxr_linenumber" name="426" href="#426">426</a>         File parentFile = file.getParentFile();
<a class="jxr_linenumber" name="427" href="#427">427</a>         File baseDirectory = <strong class="jxr_keyword">null</strong>;
<a class="jxr_linenumber" name="428" href="#428">428</a> 
<a class="jxr_linenumber" name="429" href="#429">429</a>         <strong class="jxr_keyword">if</strong> ( parentFile != <strong class="jxr_keyword">null</strong> )
<a class="jxr_linenumber" name="430" href="#430">430</a>         {
<a class="jxr_linenumber" name="431" href="#431">431</a>             baseDirectory = <strong class="jxr_keyword">new</strong> File( file.getParentFile().getAbsolutePath() );
<a class="jxr_linenumber" name="432" href="#432">432</a>         }
<a class="jxr_linenumber" name="433" href="#433">433</a>         <strong class="jxr_keyword">else</strong>
<a class="jxr_linenumber" name="434" href="#434">434</a>         {
<a class="jxr_linenumber" name="435" href="#435">435</a>             baseDirectory = <strong class="jxr_keyword">new</strong> File( <span class="jxr_string">"."</span> );
<a class="jxr_linenumber" name="436" href="#436">436</a>         }
<a class="jxr_linenumber" name="437" href="#437">437</a> 
<a class="jxr_linenumber" name="438" href="#438">438</a>         <em class="jxr_comment">// Create a temporary file in the same directory to flush the current btree</em>
<a class="jxr_linenumber" name="439" href="#439">439</a>         File tmpFileFD = File.createTempFile( <span class="jxr_string">"mavibot"</span>, <strong class="jxr_keyword">null</strong>, baseDirectory );
<a class="jxr_linenumber" name="440" href="#440">440</a>         FileOutputStream stream = <strong class="jxr_keyword">new</strong> FileOutputStream( tmpFileFD );
<a class="jxr_linenumber" name="441" href="#441">441</a>         FileChannel ch = stream.getChannel();
<a class="jxr_linenumber" name="442" href="#442">442</a> 
<a class="jxr_linenumber" name="443" href="#443">443</a>         <em class="jxr_comment">// Create a buffer containing 200 4Kb pages (around 1Mb)</em>
<a class="jxr_linenumber" name="444" href="#444">444</a>         ByteBuffer bb = ByteBuffer.allocateDirect( writeBufferSize );
<a class="jxr_linenumber" name="445" href="#445">445</a> 
<a class="jxr_linenumber" name="446" href="#446">446</a>         TupleCursor&lt;K, V&gt; cursor = browse();
<a class="jxr_linenumber" name="447" href="#447">447</a> 
<a class="jxr_linenumber" name="448" href="#448">448</a>         <strong class="jxr_keyword">if</strong> ( keySerializer == <strong class="jxr_keyword">null</strong> )
<a class="jxr_linenumber" name="449" href="#449">449</a>         {
<a class="jxr_linenumber" name="450" href="#450">450</a>             <strong class="jxr_keyword">throw</strong> <strong class="jxr_keyword">new</strong> <a href="../../../../../org/apache/directory/mavibot/btree/exception/MissingSerializerException.html">MissingSerializerException</a>( <span class="jxr_string">"Cannot flush the btree without a Key serializer"</span> );
<a class="jxr_linenumber" name="451" href="#451">451</a>         }
<a class="jxr_linenumber" name="452" href="#452">452</a> 
<a class="jxr_linenumber" name="453" href="#453">453</a>         <strong class="jxr_keyword">if</strong> ( valueSerializer == <strong class="jxr_keyword">null</strong> )
<a class="jxr_linenumber" name="454" href="#454">454</a>         {
<a class="jxr_linenumber" name="455" href="#455">455</a>             <strong class="jxr_keyword">throw</strong> <strong class="jxr_keyword">new</strong> <a href="../../../../../org/apache/directory/mavibot/btree/exception/MissingSerializerException.html">MissingSerializerException</a>( <span class="jxr_string">"Cannot flush the btree without a Value serializer"</span> );
<a class="jxr_linenumber" name="456" href="#456">456</a>         }
<a class="jxr_linenumber" name="457" href="#457">457</a> 
<a class="jxr_linenumber" name="458" href="#458">458</a>         <em class="jxr_comment">// Write the number of elements first</em>
<a class="jxr_linenumber" name="459" href="#459">459</a>         bb.putLong( btreeHeader.getNbElems() );
<a class="jxr_linenumber" name="460" href="#460">460</a> 
<a class="jxr_linenumber" name="461" href="#461">461</a>         <strong class="jxr_keyword">while</strong> ( cursor.hasNext() )
<a class="jxr_linenumber" name="462" href="#462">462</a>         {
<a class="jxr_linenumber" name="463" href="#463">463</a>             Tuple&lt;K, V&gt; tuple = cursor.next();
<a class="jxr_linenumber" name="464" href="#464">464</a> 
<a class="jxr_linenumber" name="465" href="#465">465</a>             byte[] keyBuffer = keySerializer.serialize( tuple.getKey() );
<a class="jxr_linenumber" name="466" href="#466">466</a> 
<a class="jxr_linenumber" name="467" href="#467">467</a>             writeBuffer( ch, bb, keyBuffer );
<a class="jxr_linenumber" name="468" href="#468">468</a> 
<a class="jxr_linenumber" name="469" href="#469">469</a>             byte[] valueBuffer = valueSerializer.serialize( tuple.getValue() );
<a class="jxr_linenumber" name="470" href="#470">470</a> 
<a class="jxr_linenumber" name="471" href="#471">471</a>             writeBuffer( ch, bb, valueBuffer );
<a class="jxr_linenumber" name="472" href="#472">472</a>         }
<a class="jxr_linenumber" name="473" href="#473">473</a> 
<a class="jxr_linenumber" name="474" href="#474">474</a>         <em class="jxr_comment">// Write the buffer if needed</em>
<a class="jxr_linenumber" name="475" href="#475">475</a>         <strong class="jxr_keyword">if</strong> ( bb.position() &gt; 0 )
<a class="jxr_linenumber" name="476" href="#476">476</a>         {
<a class="jxr_linenumber" name="477" href="#477">477</a>             bb.flip();
<a class="jxr_linenumber" name="478" href="#478">478</a>             ch.write( bb );
<a class="jxr_linenumber" name="479" href="#479">479</a>         }
<a class="jxr_linenumber" name="480" href="#480">480</a> 
<a class="jxr_linenumber" name="481" href="#481">481</a>         <em class="jxr_comment">// Flush to the disk for real</em>
<a class="jxr_linenumber" name="482" href="#482">482</a>         ch.force( <strong class="jxr_keyword">true</strong> );
<a class="jxr_linenumber" name="483" href="#483">483</a>         ch.close();
<a class="jxr_linenumber" name="484" href="#484">484</a> 
<a class="jxr_linenumber" name="485" href="#485">485</a>         <em class="jxr_comment">// Rename the current file to save a backup</em>
<a class="jxr_linenumber" name="486" href="#486">486</a>         File backupFile = File.createTempFile( <span class="jxr_string">"mavibot"</span>, <strong class="jxr_keyword">null</strong>, baseDirectory );
<a class="jxr_linenumber" name="487" href="#487">487</a>         file.renameTo( backupFile );
<a class="jxr_linenumber" name="488" href="#488">488</a> 
<a class="jxr_linenumber" name="489" href="#489">489</a>         <em class="jxr_comment">// Rename the temporary file to the initial file</em>
<a class="jxr_linenumber" name="490" href="#490">490</a>         tmpFileFD.renameTo( file );
<a class="jxr_linenumber" name="491" href="#491">491</a> 
<a class="jxr_linenumber" name="492" href="#492">492</a>         <em class="jxr_comment">// We can now delete the backup file</em>
<a class="jxr_linenumber" name="493" href="#493">493</a>         backupFile.delete();
<a class="jxr_linenumber" name="494" href="#494">494</a>     }
<a class="jxr_linenumber" name="495" href="#495">495</a> 
<a class="jxr_linenumber" name="496" href="#496">496</a> 
<a class="jxr_linenumber" name="497" href="#497">497</a>     <em class="jxr_javadoccomment">/**</em>
<a class="jxr_linenumber" name="498" href="#498">498</a> <em class="jxr_javadoccomment">     * Inject all the modification from the journal into the btree</em>
<a class="jxr_linenumber" name="499" href="#499">499</a> <em class="jxr_javadoccomment">     *</em>
<a class="jxr_linenumber" name="500" href="#500">500</a> <em class="jxr_javadoccomment">     * @throws IOException If we had some issue while reading the journal</em>
<a class="jxr_linenumber" name="501" href="#501">501</a> <em class="jxr_javadoccomment">     */</em>
<a class="jxr_linenumber" name="502" href="#502">502</a>     <strong class="jxr_keyword">private</strong> <strong class="jxr_keyword">void</strong> applyJournal() <strong class="jxr_keyword">throws</strong> IOException
<a class="jxr_linenumber" name="503" href="#503">503</a>     {
<a class="jxr_linenumber" name="504" href="#504">504</a>         <strong class="jxr_keyword">long</strong> revision = generateRevision();
<a class="jxr_linenumber" name="505" href="#505">505</a> 
<a class="jxr_linenumber" name="506" href="#506">506</a>         <strong class="jxr_keyword">if</strong> ( !journal.exists() )
<a class="jxr_linenumber" name="507" href="#507">507</a>         {
<a class="jxr_linenumber" name="508" href="#508">508</a>             <strong class="jxr_keyword">throw</strong> <strong class="jxr_keyword">new</strong> IOException( <span class="jxr_string">"The journal does not exist"</span> );
<a class="jxr_linenumber" name="509" href="#509">509</a>         }
<a class="jxr_linenumber" name="510" href="#510">510</a> 
<a class="jxr_linenumber" name="511" href="#511">511</a>         FileChannel channel =
<a class="jxr_linenumber" name="512" href="#512">512</a>             <strong class="jxr_keyword">new</strong> RandomAccessFile( journal, <span class="jxr_string">"rw"</span> ).getChannel();
<a class="jxr_linenumber" name="513" href="#513">513</a>         ByteBuffer buffer = ByteBuffer.allocate( 65536 );
<a class="jxr_linenumber" name="514" href="#514">514</a> 
<a class="jxr_linenumber" name="515" href="#515">515</a>         <a href="../../../../../org/apache/directory/mavibot/btree/serializer/BufferHandler.html">BufferHandler</a> bufferHandler = <strong class="jxr_keyword">new</strong> <a href="../../../../../org/apache/directory/mavibot/btree/serializer/BufferHandler.html">BufferHandler</a>( channel, buffer );
<a class="jxr_linenumber" name="516" href="#516">516</a> 
<a class="jxr_linenumber" name="517" href="#517">517</a>         <em class="jxr_comment">// Loop on all the elements, store them in lists atm</em>
<a class="jxr_linenumber" name="518" href="#518">518</a>         <strong class="jxr_keyword">try</strong>
<a class="jxr_linenumber" name="519" href="#519">519</a>         {
<a class="jxr_linenumber" name="520" href="#520">520</a>             <strong class="jxr_keyword">while</strong> ( <strong class="jxr_keyword">true</strong> )
<a class="jxr_linenumber" name="521" href="#521">521</a>             {
<a class="jxr_linenumber" name="522" href="#522">522</a>                 <em class="jxr_comment">// Read the type</em>
<a class="jxr_linenumber" name="523" href="#523">523</a>                 byte[] type = bufferHandler.read( 1 );
<a class="jxr_linenumber" name="524" href="#524">524</a> 
<a class="jxr_linenumber" name="525" href="#525">525</a>                 <strong class="jxr_keyword">if</strong> ( type[0] == Modification.ADDITION )
<a class="jxr_linenumber" name="526" href="#526">526</a>                 {
<a class="jxr_linenumber" name="527" href="#527">527</a>                     <em class="jxr_comment">// Read the key</em>
<a class="jxr_linenumber" name="528" href="#528">528</a>                     K key = keySerializer.deserialize( bufferHandler );
<a class="jxr_linenumber" name="529" href="#529">529</a> 
<a class="jxr_linenumber" name="530" href="#530">530</a>                     <em class="jxr_comment">//keys.add( key );</em>
<a class="jxr_linenumber" name="531" href="#531">531</a> 
<a class="jxr_linenumber" name="532" href="#532">532</a>                     <em class="jxr_comment">// Read the value</em>
<a class="jxr_linenumber" name="533" href="#533">533</a>                     V value = valueSerializer.deserialize( bufferHandler );
<a class="jxr_linenumber" name="534" href="#534">534</a> 
<a class="jxr_linenumber" name="535" href="#535">535</a>                     <em class="jxr_comment">//values.add( value );</em>
<a class="jxr_linenumber" name="536" href="#536">536</a> 
<a class="jxr_linenumber" name="537" href="#537">537</a>                     <em class="jxr_comment">// Inject the data in the tree. (to be replaced by a bulk load)</em>
<a class="jxr_linenumber" name="538" href="#538">538</a>                     insert( key, value, revision );
<a class="jxr_linenumber" name="539" href="#539">539</a>                 }
<a class="jxr_linenumber" name="540" href="#540">540</a>                 <strong class="jxr_keyword">else</strong>
<a class="jxr_linenumber" name="541" href="#541">541</a>                 {
<a class="jxr_linenumber" name="542" href="#542">542</a>                     <em class="jxr_comment">// Read the key</em>
<a class="jxr_linenumber" name="543" href="#543">543</a>                     K key = keySerializer.deserialize( bufferHandler );
<a class="jxr_linenumber" name="544" href="#544">544</a> 
<a class="jxr_linenumber" name="545" href="#545">545</a>                     <em class="jxr_comment">// Remove the key from the tree</em>
<a class="jxr_linenumber" name="546" href="#546">546</a>                     delete( key, revision );
<a class="jxr_linenumber" name="547" href="#547">547</a>                 }
<a class="jxr_linenumber" name="548" href="#548">548</a>             }
<a class="jxr_linenumber" name="549" href="#549">549</a>         }
<a class="jxr_linenumber" name="550" href="#550">550</a>         <strong class="jxr_keyword">catch</strong> ( EOFException eofe )
<a class="jxr_linenumber" name="551" href="#551">551</a>         {
<a class="jxr_linenumber" name="552" href="#552">552</a>             eofe.printStackTrace();
<a class="jxr_linenumber" name="553" href="#553">553</a>             <em class="jxr_comment">// Done reading the journal. truncate it</em>
<a class="jxr_linenumber" name="554" href="#554">554</a>             journalChannel.truncate( 0 );
<a class="jxr_linenumber" name="555" href="#555">555</a>         }
<a class="jxr_linenumber" name="556" href="#556">556</a>     }
<a class="jxr_linenumber" name="557" href="#557">557</a> 
<a class="jxr_linenumber" name="558" href="#558">558</a> 
<a class="jxr_linenumber" name="559" href="#559">559</a>     <em class="jxr_javadoccomment">/**</em>
<a class="jxr_linenumber" name="560" href="#560">560</a> <em class="jxr_javadoccomment">     * Read the data from the disk into this BTree. All the existing data in the</em>
<a class="jxr_linenumber" name="561" href="#561">561</a> <em class="jxr_javadoccomment">     * BTree are kept, the read data will be associated with a new revision.</em>
<a class="jxr_linenumber" name="562" href="#562">562</a> <em class="jxr_javadoccomment">     *</em>
<a class="jxr_linenumber" name="563" href="#563">563</a> <em class="jxr_javadoccomment">     * @param file</em>
<a class="jxr_linenumber" name="564" href="#564">564</a> <em class="jxr_javadoccomment">     * @throws IOException</em>
<a class="jxr_linenumber" name="565" href="#565">565</a> <em class="jxr_javadoccomment">     */</em>
<a class="jxr_linenumber" name="566" href="#566">566</a>     <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">void</strong> load( File file ) <strong class="jxr_keyword">throws</strong> IOException
<a class="jxr_linenumber" name="567" href="#567">567</a>     {
<a class="jxr_linenumber" name="568" href="#568">568</a>         <strong class="jxr_keyword">long</strong> revision = generateRevision();
<a class="jxr_linenumber" name="569" href="#569">569</a> 
<a class="jxr_linenumber" name="570" href="#570">570</a>         <strong class="jxr_keyword">if</strong> ( !file.exists() )
<a class="jxr_linenumber" name="571" href="#571">571</a>         {
<a class="jxr_linenumber" name="572" href="#572">572</a>             <strong class="jxr_keyword">throw</strong> <strong class="jxr_keyword">new</strong> IOException( <span class="jxr_string">"The file does not exist"</span> );
<a class="jxr_linenumber" name="573" href="#573">573</a>         }
<a class="jxr_linenumber" name="574" href="#574">574</a> 
<a class="jxr_linenumber" name="575" href="#575">575</a>         FileChannel channel =
<a class="jxr_linenumber" name="576" href="#576">576</a>             <strong class="jxr_keyword">new</strong> RandomAccessFile( file, <span class="jxr_string">"rw"</span> ).getChannel();
<a class="jxr_linenumber" name="577" href="#577">577</a>         ByteBuffer buffer = ByteBuffer.allocate( 65536 );
<a class="jxr_linenumber" name="578" href="#578">578</a> 
<a class="jxr_linenumber" name="579" href="#579">579</a>         <a href="../../../../../org/apache/directory/mavibot/btree/serializer/BufferHandler.html">BufferHandler</a> bufferHandler = <strong class="jxr_keyword">new</strong> <a href="../../../../../org/apache/directory/mavibot/btree/serializer/BufferHandler.html">BufferHandler</a>( channel, buffer );
<a class="jxr_linenumber" name="580" href="#580">580</a> 
<a class="jxr_linenumber" name="581" href="#581">581</a>         <strong class="jxr_keyword">long</strong> nbElems = LongSerializer.deserialize( bufferHandler.read( 8 ) );
<a class="jxr_linenumber" name="582" href="#582">582</a>         btreeHeader.setNbElems( nbElems );
<a class="jxr_linenumber" name="583" href="#583">583</a> 
<a class="jxr_linenumber" name="584" href="#584">584</a>         <em class="jxr_comment">// Prepare a list of keys and values read from the disk</em>
<a class="jxr_linenumber" name="585" href="#585">585</a>         <em class="jxr_comment">//List&lt;K&gt; keys = new ArrayList&lt;K&gt;();</em>
<a class="jxr_linenumber" name="586" href="#586">586</a>         <em class="jxr_comment">//List&lt;V&gt; values = new ArrayList&lt;V&gt;();</em>
<a class="jxr_linenumber" name="587" href="#587">587</a> 
<a class="jxr_linenumber" name="588" href="#588">588</a>         <em class="jxr_comment">// desactivate the journal while we load the file</em>
<a class="jxr_linenumber" name="589" href="#589">589</a>         <strong class="jxr_keyword">boolean</strong> isJournalActivated = withJournal;
<a class="jxr_linenumber" name="590" href="#590">590</a> 
<a class="jxr_linenumber" name="591" href="#591">591</a>         withJournal = false;
<a class="jxr_linenumber" name="592" href="#592">592</a> 
<a class="jxr_linenumber" name="593" href="#593">593</a>         <em class="jxr_comment">// Loop on all the elements, store them in lists atm</em>
<a class="jxr_linenumber" name="594" href="#594">594</a>         <strong class="jxr_keyword">for</strong> ( <strong class="jxr_keyword">long</strong> i = 0; i &lt; nbElems; i++ )
<a class="jxr_linenumber" name="595" href="#595">595</a>         {
<a class="jxr_linenumber" name="596" href="#596">596</a>             <em class="jxr_comment">// Read the key</em>
<a class="jxr_linenumber" name="597" href="#597">597</a>             K key = keySerializer.deserialize( bufferHandler );
<a class="jxr_linenumber" name="598" href="#598">598</a> 
<a class="jxr_linenumber" name="599" href="#599">599</a>             <em class="jxr_comment">//keys.add( key );</em>
<a class="jxr_linenumber" name="600" href="#600">600</a> 
<a class="jxr_linenumber" name="601" href="#601">601</a>             <em class="jxr_comment">// Read the value</em>
<a class="jxr_linenumber" name="602" href="#602">602</a>             V value = valueSerializer.deserialize( bufferHandler );
<a class="jxr_linenumber" name="603" href="#603">603</a> 
<a class="jxr_linenumber" name="604" href="#604">604</a>             <em class="jxr_comment">//values.add( value );</em>
<a class="jxr_linenumber" name="605" href="#605">605</a> 
<a class="jxr_linenumber" name="606" href="#606">606</a>             <em class="jxr_comment">// Inject the data in the tree. (to be replaced by a bulk load)</em>
<a class="jxr_linenumber" name="607" href="#607">607</a>             insert( key, value, revision );
<a class="jxr_linenumber" name="608" href="#608">608</a>         }
<a class="jxr_linenumber" name="609" href="#609">609</a> 
<a class="jxr_linenumber" name="610" href="#610">610</a>         <em class="jxr_comment">// Restore the withJournal value</em>
<a class="jxr_linenumber" name="611" href="#611">611</a>         withJournal = isJournalActivated;
<a class="jxr_linenumber" name="612" href="#612">612</a> 
<a class="jxr_linenumber" name="613" href="#613">613</a>         <em class="jxr_comment">// Now, process the lists to create the btree</em>
<a class="jxr_linenumber" name="614" href="#614">614</a>         <em class="jxr_comment">// TODO... BulkLoad</em>
<a class="jxr_linenumber" name="615" href="#615">615</a>     }
<a class="jxr_linenumber" name="616" href="#616">616</a> 
<a class="jxr_linenumber" name="617" href="#617">617</a> 
<a class="jxr_linenumber" name="618" href="#618">618</a>     <em class="jxr_javadoccomment">/**</em>
<a class="jxr_linenumber" name="619" href="#619">619</a> <em class="jxr_javadoccomment">     * Get the rootPzge associated to a give revision.</em>
<a class="jxr_linenumber" name="620" href="#620">620</a> <em class="jxr_javadoccomment">     *</em>
<a class="jxr_linenumber" name="621" href="#621">621</a> <em class="jxr_javadoccomment">     * @param revision The revision we are looking for</em>
<a class="jxr_linenumber" name="622" href="#622">622</a> <em class="jxr_javadoccomment">     * @return The rootPage associated to this revision</em>
<a class="jxr_linenumber" name="623" href="#623">623</a> <em class="jxr_javadoccomment">     * @throws IOException If we had an issue while accessing the underlying file</em>
<a class="jxr_linenumber" name="624" href="#624">624</a> <em class="jxr_javadoccomment">     * @throws KeyNotFoundException If the revision does not exist for this Btree</em>
<a class="jxr_linenumber" name="625" href="#625">625</a> <em class="jxr_javadoccomment">     */</em>
<a class="jxr_linenumber" name="626" href="#626">626</a>     <strong class="jxr_keyword">public</strong> Page&lt;K, V&gt; getRootPage( <strong class="jxr_keyword">long</strong> revision ) <strong class="jxr_keyword">throws</strong> IOException, KeyNotFoundException
<a class="jxr_linenumber" name="627" href="#627">627</a>     {
<a class="jxr_linenumber" name="628" href="#628">628</a>         <em class="jxr_comment">// Atm, the in-memory BTree does not support searches in many revisions</em>
<a class="jxr_linenumber" name="629" href="#629">629</a>         <strong class="jxr_keyword">return</strong> rootPage;
<a class="jxr_linenumber" name="630" href="#630">630</a>     }
<a class="jxr_linenumber" name="631" href="#631">631</a> 
<a class="jxr_linenumber" name="632" href="#632">632</a> 
<a class="jxr_linenumber" name="633" href="#633">633</a>     <em class="jxr_javadoccomment">/**</em>
<a class="jxr_linenumber" name="634" href="#634">634</a> <em class="jxr_javadoccomment">     * Flush the latest revision to disk. We will replace the current file by the new one, as</em>
<a class="jxr_linenumber" name="635" href="#635">635</a> <em class="jxr_javadoccomment">     * we flush in a temporary file.</em>
<a class="jxr_linenumber" name="636" href="#636">636</a> <em class="jxr_javadoccomment">     */</em>
<a class="jxr_linenumber" name="637" href="#637">637</a>     <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">void</strong> flush() <strong class="jxr_keyword">throws</strong> IOException
<a class="jxr_linenumber" name="638" href="#638">638</a>     {
<a class="jxr_linenumber" name="639" href="#639">639</a>         <strong class="jxr_keyword">if</strong> ( getType() == BTreeTypeEnum.BACKED_ON_DISK )
<a class="jxr_linenumber" name="640" href="#640">640</a>         {
<a class="jxr_linenumber" name="641" href="#641">641</a>             <em class="jxr_comment">// Then flush the file</em>
<a class="jxr_linenumber" name="642" href="#642">642</a>             flush( file );
<a class="jxr_linenumber" name="643" href="#643">643</a>             journalChannel.truncate( 0 );
<a class="jxr_linenumber" name="644" href="#644">644</a>         }
<a class="jxr_linenumber" name="645" href="#645">645</a>     }
<a class="jxr_linenumber" name="646" href="#646">646</a> 
<a class="jxr_linenumber" name="647" href="#647">647</a> 
<a class="jxr_linenumber" name="648" href="#648">648</a>     <em class="jxr_javadoccomment">/**</em>
<a class="jxr_linenumber" name="649" href="#649">649</a> <em class="jxr_javadoccomment">     * @return the file</em>
<a class="jxr_linenumber" name="650" href="#650">650</a> <em class="jxr_javadoccomment">     */</em>
<a class="jxr_linenumber" name="651" href="#651">651</a>     <strong class="jxr_keyword">public</strong> File getFile()
<a class="jxr_linenumber" name="652" href="#652">652</a>     {
<a class="jxr_linenumber" name="653" href="#653">653</a>         <strong class="jxr_keyword">return</strong> file;
<a class="jxr_linenumber" name="654" href="#654">654</a>     }
<a class="jxr_linenumber" name="655" href="#655">655</a> 
<a class="jxr_linenumber" name="656" href="#656">656</a> 
<a class="jxr_linenumber" name="657" href="#657">657</a>     <em class="jxr_javadoccomment">/**</em>
<a class="jxr_linenumber" name="658" href="#658">658</a> <em class="jxr_javadoccomment">     * @return the journal</em>
<a class="jxr_linenumber" name="659" href="#659">659</a> <em class="jxr_javadoccomment">     */</em>
<a class="jxr_linenumber" name="660" href="#660">660</a>     <strong class="jxr_keyword">public</strong> File getJournal()
<a class="jxr_linenumber" name="661" href="#661">661</a>     {
<a class="jxr_linenumber" name="662" href="#662">662</a>         <strong class="jxr_keyword">return</strong> journal;
<a class="jxr_linenumber" name="663" href="#663">663</a>     }
<a class="jxr_linenumber" name="664" href="#664">664</a> 
<a class="jxr_linenumber" name="665" href="#665">665</a> 
<a class="jxr_linenumber" name="666" href="#666">666</a>     <em class="jxr_javadoccomment">/**</em>
<a class="jxr_linenumber" name="667" href="#667">667</a> <em class="jxr_javadoccomment">     * @return true if the BTree is fully in memory</em>
<a class="jxr_linenumber" name="668" href="#668">668</a> <em class="jxr_javadoccomment">     */</em>
<a class="jxr_linenumber" name="669" href="#669">669</a>     <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">boolean</strong> isInMemory()
<a class="jxr_linenumber" name="670" href="#670">670</a>     {
<a class="jxr_linenumber" name="671" href="#671">671</a>         <strong class="jxr_keyword">return</strong> getType() == BTreeTypeEnum.IN_MEMORY;
<a class="jxr_linenumber" name="672" href="#672">672</a>     }
<a class="jxr_linenumber" name="673" href="#673">673</a> 
<a class="jxr_linenumber" name="674" href="#674">674</a> 
<a class="jxr_linenumber" name="675" href="#675">675</a>     <em class="jxr_javadoccomment">/**</em>
<a class="jxr_linenumber" name="676" href="#676">676</a> <em class="jxr_javadoccomment">     * @return true if the BTree is persisted on disk</em>
<a class="jxr_linenumber" name="677" href="#677">677</a> <em class="jxr_javadoccomment">     */</em>
<a class="jxr_linenumber" name="678" href="#678">678</a>     <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">boolean</strong> isPersistent()
<a class="jxr_linenumber" name="679" href="#679">679</a>     {
<a class="jxr_linenumber" name="680" href="#680">680</a>         <strong class="jxr_keyword">return</strong> getType() == BTreeTypeEnum.IN_MEMORY;
<a class="jxr_linenumber" name="681" href="#681">681</a>     }
<a class="jxr_linenumber" name="682" href="#682">682</a> 
<a class="jxr_linenumber" name="683" href="#683">683</a> 
<a class="jxr_linenumber" name="684" href="#684">684</a>     <strong class="jxr_keyword">private</strong> <strong class="jxr_keyword">void</strong> writeToJournal( Modification&lt;K, V&gt; modification )
<a class="jxr_linenumber" name="685" href="#685">685</a>         <strong class="jxr_keyword">throws</strong> IOException
<a class="jxr_linenumber" name="686" href="#686">686</a>     {
<a class="jxr_linenumber" name="687" href="#687">687</a>         <strong class="jxr_keyword">if</strong> ( modification instanceof Addition )
<a class="jxr_linenumber" name="688" href="#688">688</a>         {
<a class="jxr_linenumber" name="689" href="#689">689</a>             byte[] keyBuffer = keySerializer.serialize( modification.getKey() );
<a class="jxr_linenumber" name="690" href="#690">690</a>             ByteBuffer bb = ByteBuffer.allocateDirect( keyBuffer.length + 1 );
<a class="jxr_linenumber" name="691" href="#691">691</a>             bb.put( Modification.ADDITION );
<a class="jxr_linenumber" name="692" href="#692">692</a>             bb.put( keyBuffer );
<a class="jxr_linenumber" name="693" href="#693">693</a>             bb.flip();
<a class="jxr_linenumber" name="694" href="#694">694</a> 
<a class="jxr_linenumber" name="695" href="#695">695</a>             journalChannel.write( bb );
<a class="jxr_linenumber" name="696" href="#696">696</a> 
<a class="jxr_linenumber" name="697" href="#697">697</a>             byte[] valueBuffer = valueSerializer.serialize( modification.getValue() );
<a class="jxr_linenumber" name="698" href="#698">698</a>             bb = ByteBuffer.allocateDirect( valueBuffer.length );
<a class="jxr_linenumber" name="699" href="#699">699</a>             bb.put( valueBuffer );
<a class="jxr_linenumber" name="700" href="#700">700</a>             bb.flip();
<a class="jxr_linenumber" name="701" href="#701">701</a> 
<a class="jxr_linenumber" name="702" href="#702">702</a>             journalChannel.write( bb );
<a class="jxr_linenumber" name="703" href="#703">703</a>         }
<a class="jxr_linenumber" name="704" href="#704">704</a>         <strong class="jxr_keyword">else</strong> <strong class="jxr_keyword">if</strong> ( modification instanceof Deletion )
<a class="jxr_linenumber" name="705" href="#705">705</a>         {
<a class="jxr_linenumber" name="706" href="#706">706</a>             byte[] keyBuffer = keySerializer.serialize( modification.getKey() );
<a class="jxr_linenumber" name="707" href="#707">707</a>             ByteBuffer bb = ByteBuffer.allocateDirect( keyBuffer.length + 1 );
<a class="jxr_linenumber" name="708" href="#708">708</a>             bb.put( Modification.DELETION );
<a class="jxr_linenumber" name="709" href="#709">709</a>             bb.put( keyBuffer );
<a class="jxr_linenumber" name="710" href="#710">710</a>             bb.flip();
<a class="jxr_linenumber" name="711" href="#711">711</a> 
<a class="jxr_linenumber" name="712" href="#712">712</a>             journalChannel.write( bb );
<a class="jxr_linenumber" name="713" href="#713">713</a>         }
<a class="jxr_linenumber" name="714" href="#714">714</a> 
<a class="jxr_linenumber" name="715" href="#715">715</a>         <em class="jxr_comment">// Flush to the disk for real</em>
<a class="jxr_linenumber" name="716" href="#716">716</a>         journalChannel.force( <strong class="jxr_keyword">true</strong> );
<a class="jxr_linenumber" name="717" href="#717">717</a>     }
<a class="jxr_linenumber" name="718" href="#718">718</a> 
<a class="jxr_linenumber" name="719" href="#719">719</a> 
<a class="jxr_linenumber" name="720" href="#720">720</a>     <em class="jxr_javadoccomment">/**</em>
<a class="jxr_linenumber" name="721" href="#721">721</a> <em class="jxr_javadoccomment">     * Starts a transaction</em>
<a class="jxr_linenumber" name="722" href="#722">722</a> <em class="jxr_javadoccomment">     */</em>
<a class="jxr_linenumber" name="723" href="#723">723</a>     <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">void</strong> beginTransaction()
<a class="jxr_linenumber" name="724" href="#724">724</a>     {
<a class="jxr_linenumber" name="725" href="#725">725</a>         <em class="jxr_comment">// Does nothing...</em>
<a class="jxr_linenumber" name="726" href="#726">726</a>     }
<a class="jxr_linenumber" name="727" href="#727">727</a> 
<a class="jxr_linenumber" name="728" href="#728">728</a> 
<a class="jxr_linenumber" name="729" href="#729">729</a>     <em class="jxr_javadoccomment">/**</em>
<a class="jxr_linenumber" name="730" href="#730">730</a> <em class="jxr_javadoccomment">     * Commits a transaction</em>
<a class="jxr_linenumber" name="731" href="#731">731</a> <em class="jxr_javadoccomment">     */</em>
<a class="jxr_linenumber" name="732" href="#732">732</a>     <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">void</strong> commit()
<a class="jxr_linenumber" name="733" href="#733">733</a>     {
<a class="jxr_linenumber" name="734" href="#734">734</a>         <em class="jxr_comment">// Does nothing...</em>
<a class="jxr_linenumber" name="735" href="#735">735</a>     }
<a class="jxr_linenumber" name="736" href="#736">736</a> 
<a class="jxr_linenumber" name="737" href="#737">737</a> 
<a class="jxr_linenumber" name="738" href="#738">738</a>     <em class="jxr_javadoccomment">/**</em>
<a class="jxr_linenumber" name="739" href="#739">739</a> <em class="jxr_javadoccomment">     * Rollback a transaction</em>
<a class="jxr_linenumber" name="740" href="#740">740</a> <em class="jxr_javadoccomment">     */</em>
<a class="jxr_linenumber" name="741" href="#741">741</a>     <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">void</strong> rollback()
<a class="jxr_linenumber" name="742" href="#742">742</a>     {
<a class="jxr_linenumber" name="743" href="#743">743</a>         <em class="jxr_comment">// Does nothing...</em>
<a class="jxr_linenumber" name="744" href="#744">744</a>     }
<a class="jxr_linenumber" name="745" href="#745">745</a> 
<a class="jxr_linenumber" name="746" href="#746">746</a> 
<a class="jxr_linenumber" name="747" href="#747">747</a>     <em class="jxr_javadoccomment">/**</em>
<a class="jxr_linenumber" name="748" href="#748">748</a> <em class="jxr_javadoccomment">     * @see Object#toString()</em>
<a class="jxr_linenumber" name="749" href="#749">749</a> <em class="jxr_javadoccomment">     */</em>
<a class="jxr_linenumber" name="750" href="#750">750</a>     <strong class="jxr_keyword">public</strong> String toString()
<a class="jxr_linenumber" name="751" href="#751">751</a>     {
<a class="jxr_linenumber" name="752" href="#752">752</a>         StringBuilder sb = <strong class="jxr_keyword">new</strong> StringBuilder();
<a class="jxr_linenumber" name="753" href="#753">753</a> 
<a class="jxr_linenumber" name="754" href="#754">754</a>         <strong class="jxr_keyword">switch</strong> ( getType() )
<a class="jxr_linenumber" name="755" href="#755">755</a>         {
<a class="jxr_linenumber" name="756" href="#756">756</a>             <strong class="jxr_keyword">case</strong> IN_MEMORY:
<a class="jxr_linenumber" name="757" href="#757">757</a>                 sb.append( <span class="jxr_string">"In-memory "</span> );
<a class="jxr_linenumber" name="758" href="#758">758</a>                 <strong class="jxr_keyword">break</strong>;
<a class="jxr_linenumber" name="759" href="#759">759</a> 
<a class="jxr_linenumber" name="760" href="#760">760</a>             <strong class="jxr_keyword">case</strong> BACKED_ON_DISK:
<a class="jxr_linenumber" name="761" href="#761">761</a>                 sb.append( <span class="jxr_string">"Persistent "</span> );
<a class="jxr_linenumber" name="762" href="#762">762</a>                 <strong class="jxr_keyword">break</strong>;
<a class="jxr_linenumber" name="763" href="#763">763</a> 
<a class="jxr_linenumber" name="764" href="#764">764</a>         }
<a class="jxr_linenumber" name="765" href="#765">765</a> 
<a class="jxr_linenumber" name="766" href="#766">766</a>         sb.append( <span class="jxr_string">"BTree"</span> );
<a class="jxr_linenumber" name="767" href="#767">767</a>         sb.append( <span class="jxr_string">"["</span> ).append( btreeHeader.getName() ).append( <span class="jxr_string">"]"</span> );
<a class="jxr_linenumber" name="768" href="#768">768</a>         sb.append( <span class="jxr_string">"( pageSize:"</span> ).append( btreeHeader.getPageSize() );
<a class="jxr_linenumber" name="769" href="#769">769</a> 
<a class="jxr_linenumber" name="770" href="#770">770</a>         <strong class="jxr_keyword">if</strong> ( rootPage != <strong class="jxr_keyword">null</strong> )
<a class="jxr_linenumber" name="771" href="#771">771</a>         {
<a class="jxr_linenumber" name="772" href="#772">772</a>             sb.append( <span class="jxr_string">", nbEntries:"</span> ).append( btreeHeader.getNbElems() );
<a class="jxr_linenumber" name="773" href="#773">773</a>         }
<a class="jxr_linenumber" name="774" href="#774">774</a>         <strong class="jxr_keyword">else</strong>
<a class="jxr_linenumber" name="775" href="#775">775</a>         {
<a class="jxr_linenumber" name="776" href="#776">776</a>             sb.append( <span class="jxr_string">", nbEntries:"</span> ).append( 0 );
<a class="jxr_linenumber" name="777" href="#777">777</a>         }
<a class="jxr_linenumber" name="778" href="#778">778</a> 
<a class="jxr_linenumber" name="779" href="#779">779</a>         sb.append( <span class="jxr_string">", comparator:"</span> );
<a class="jxr_linenumber" name="780" href="#780">780</a> 
<a class="jxr_linenumber" name="781" href="#781">781</a>         <strong class="jxr_keyword">if</strong> ( keySerializer.getComparator() == <strong class="jxr_keyword">null</strong> )
<a class="jxr_linenumber" name="782" href="#782">782</a>         {
<a class="jxr_linenumber" name="783" href="#783">783</a>             sb.append( <span class="jxr_string">"null"</span> );
<a class="jxr_linenumber" name="784" href="#784">784</a>         }
<a class="jxr_linenumber" name="785" href="#785">785</a>         <strong class="jxr_keyword">else</strong>
<a class="jxr_linenumber" name="786" href="#786">786</a>         {
<a class="jxr_linenumber" name="787" href="#787">787</a>             sb.append( keySerializer.getComparator().getClass().getSimpleName() );
<a class="jxr_linenumber" name="788" href="#788">788</a>         }
<a class="jxr_linenumber" name="789" href="#789">789</a> 
<a class="jxr_linenumber" name="790" href="#790">790</a>         sb.append( <span class="jxr_string">", DuplicatesAllowed: "</span> ).append( btreeHeader.isAllowDuplicates() );
<a class="jxr_linenumber" name="791" href="#791">791</a> 
<a class="jxr_linenumber" name="792" href="#792">792</a>         <strong class="jxr_keyword">if</strong> ( getType() == BTreeTypeEnum.BACKED_ON_DISK )
<a class="jxr_linenumber" name="793" href="#793">793</a>         {
<a class="jxr_linenumber" name="794" href="#794">794</a>             <strong class="jxr_keyword">try</strong>
<a class="jxr_linenumber" name="795" href="#795">795</a>             {
<a class="jxr_linenumber" name="796" href="#796">796</a>                 sb.append( <span class="jxr_string">", file : "</span> );
<a class="jxr_linenumber" name="797" href="#797">797</a> 
<a class="jxr_linenumber" name="798" href="#798">798</a>                 <strong class="jxr_keyword">if</strong> ( file != <strong class="jxr_keyword">null</strong> )
<a class="jxr_linenumber" name="799" href="#799">799</a>                 {
<a class="jxr_linenumber" name="800" href="#800">800</a>                     sb.append( file.getCanonicalPath() );
<a class="jxr_linenumber" name="801" href="#801">801</a>                 }
<a class="jxr_linenumber" name="802" href="#802">802</a>                 <strong class="jxr_keyword">else</strong>
<a class="jxr_linenumber" name="803" href="#803">803</a>                 {
<a class="jxr_linenumber" name="804" href="#804">804</a>                     sb.append( <span class="jxr_string">"Unknown"</span> );
<a class="jxr_linenumber" name="805" href="#805">805</a>                 }
<a class="jxr_linenumber" name="806" href="#806">806</a> 
<a class="jxr_linenumber" name="807" href="#807">807</a>                 sb.append( <span class="jxr_string">", journal : "</span> );
<a class="jxr_linenumber" name="808" href="#808">808</a> 
<a class="jxr_linenumber" name="809" href="#809">809</a>                 <strong class="jxr_keyword">if</strong> ( journal != <strong class="jxr_keyword">null</strong> )
<a class="jxr_linenumber" name="810" href="#810">810</a>                 {
<a class="jxr_linenumber" name="811" href="#811">811</a>                     sb.append( journal.getCanonicalPath() );
<a class="jxr_linenumber" name="812" href="#812">812</a>                 }
<a class="jxr_linenumber" name="813" href="#813">813</a>                 <strong class="jxr_keyword">else</strong>
<a class="jxr_linenumber" name="814" href="#814">814</a>                 {
<a class="jxr_linenumber" name="815" href="#815">815</a>                     sb.append( <span class="jxr_string">"Unkown"</span> );
<a class="jxr_linenumber" name="816" href="#816">816</a>                 }
<a class="jxr_linenumber" name="817" href="#817">817</a>             }
<a class="jxr_linenumber" name="818" href="#818">818</a>             <strong class="jxr_keyword">catch</strong> ( IOException ioe )
<a class="jxr_linenumber" name="819" href="#819">819</a>             {
<a class="jxr_linenumber" name="820" href="#820">820</a>                 <em class="jxr_comment">// There is little we can do here...</em>
<a class="jxr_linenumber" name="821" href="#821">821</a>             }
<a class="jxr_linenumber" name="822" href="#822">822</a>         }
<a class="jxr_linenumber" name="823" href="#823">823</a> 
<a class="jxr_linenumber" name="824" href="#824">824</a>         sb.append( <span class="jxr_string">") : \n"</span> );
<a class="jxr_linenumber" name="825" href="#825">825</a>         sb.append( rootPage.dumpPage( <span class="jxr_string">""</span> ) );
<a class="jxr_linenumber" name="826" href="#826">826</a> 
<a class="jxr_linenumber" name="827" href="#827">827</a>         <strong class="jxr_keyword">return</strong> sb.toString();
<a class="jxr_linenumber" name="828" href="#828">828</a>     }
<a class="jxr_linenumber" name="829" href="#829">829</a> }
</pre>
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